U.S. patent application number 11/025733 was filed with the patent office on 2005-10-13 for push-button switch with improved movable contact.
This patent application is currently assigned to HON HAI PRECISION IND. CO., LTD.. Invention is credited to Liu, Yan Min, Yu, Wei.
Application Number | 20050224330 11/025733 |
Document ID | / |
Family ID | 35059435 |
Filed Date | 2005-10-13 |
United States Patent
Application |
20050224330 |
Kind Code |
A1 |
Liu, Yan Min ; et
al. |
October 13, 2005 |
Push-button switch with improved movable contact
Abstract
A push-button switch includes an insulative housing (1), a
central fixed contact (412), a pair of side fixed contacts (422), a
movable contact (3), an actuator (5) and a cover (2). The cover
engages with the housing and defines a guiding hole (210). The
central fixed contact and the side fixed contacts are fixed in the
housing, of which the side fixed contacts surround the central
fixed contact, and each has a pair of fixed contact terminals (411
or 421) extending out the housing. The movable contact is disposed
over the fixed contacts. The movable contact has a pair of side
contacting portions (35) and a central contacting portion (33). The
side contacting portions contact with the side fixed contacts. The
central fixed contacting portion is capable of contacting the
central fixed contact by resilient deformation. The actuator is
disposed on the movable contact and has an operating portion (52)
projecting beyond the guiding hole of the cover. The actuator
actuates the movable contact to contact the fixed contact.
Inventors: |
Liu, Yan Min; (Shenzhen,
CN) ; Yu, Wei; (Shenzhen, CN) |
Correspondence
Address: |
WEI TE CHUNG
FOXCONN INTERNATIONAL, INC.
1650 MEMOREX DRIVE
SANTA CLARA
CA
95050
US
|
Assignee: |
HON HAI PRECISION IND. CO.,
LTD.
|
Family ID: |
35059435 |
Appl. No.: |
11/025733 |
Filed: |
December 28, 2004 |
Current U.S.
Class: |
200/345 ;
200/344; 200/406 |
Current CPC
Class: |
H01H 13/48 20130101;
H01H 2221/064 20130101 |
Class at
Publication: |
200/345 ;
200/406; 200/344 |
International
Class: |
H01H 009/26; H01H
013/70 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 9, 2004 |
TW |
93109868 |
Claims
We claim:
1. A push-button switch comprising: an insulative housing having a
base; a cover engaging with the housing and defining a guiding
hole; a central fixed contact strip fixed in the housing and having
terminals extending out the housing; a side fixed contact strip
fixed in the housing and including a pair of side fixed contacts
and a pair of terminals extending out the housing, the side fixed
contacts surrounding the central fixed contact; a movable contact
received in the housing and disposed over the fixed contacts, and
having a pair of side contacting portions correspondingly
contacting with side fixed contacts and a central contacting
portion capable of contacting the central fixed contact by
resilient deformation; an actuator received in the housing, being
disposed on the movable contact and having an operating portion
projecting beyond the guiding hole of the cover, actuating the
movable contact to contact the fixed contact; and wherein the
movable contact has an interconnecting portion and a plurality of
slits to alleviate the stress.
2. The push-button switch as claimed in claim 1, wherein the
movable contact has a periphery frame, an inner frame and an
interconnecting portion interconnecting the periphery frame and the
inner frame.
3. The push-button switch as claimed in claim 2, wherein the side
contacting portions are defined at opposite edges of the periphery
frame by bending down folding portions thereof, and the central
contacting portion is defined in the inner frame by providing a
pair of inner slits parallelly defined along.
4. The push-button switch as claimed in claim 3, wherein a
periphery slit is defined in the periphery frame between the
interconnecting portion and a corresponding side contacting
portion.
5. The push-button switch as claimed in claim 2, wherein a pair of
opposite C-shaped slits is defined between the inner frame and the
periphery frame in a longitudinal direction.
6. The push-button switch as claimed in claim 1, wherein the
housing has a plurality of positioning posts, the cover defines a
plurality of positioning holes, and the positioning posts couple
with the positioning holes.
7. A push-button switch comprising: an insulative housing defining
a center portion and a periphery portion; a first fixed contact set
located in said center portion; a second fixed contact set located
in said periphery portion; a moveable contact located above said
first and second fixed contact sets, and including an immoveable
outer frame constantly engaged with the second fixed contact set,
and a moveable inner frame located right above the first fixed
contact set, said inner frame being initially upwardly
symmetrically curved along a first direction while being adapted to
be downwardly symmetrically curved when a downward force is applied
thereon so as to be mechanically and electrically engaged the first
fixed contact set thereunder, wherein said inner frame is not
directly linked to the outer frame in said first direction but via
a downwardly deflectable interconnecting portion which is directly
linked to the outer frame in said first direction.
8. The push-button switch as claimed in claim 7, wherein said inner
frame is linked to the interconnecting portion in a second
direction transverse to said first direction.
9. The push-button switch as claimed in claim 7, wherein both said
inner frame and said outer frame are rectangular.
10. A contact arrangement for use within a switch, comprising: a
first fixed contact set located in a center portion; a second fixed
contact set located in a periphery portion surrounding said center
portion; a moveable contact located above said first and second
fixed contact sets, and including an immoveable outer frame
constantly engaged with the second fixed contact set, and a
moveable inner frame located right above the first fixed contact
set, said inner frame being not directly linked to the outer frame
but via a downwardly deflectable interconnecting portion which is
not located right above the first fixed contact set while being
directly linked to the outer frame; wherein both said
interconnecting portion and said inner frame are upwardly bowed in
a relaxed manner while both being downwardly deformably bowed in a
stressed manner to have the inner frame mechanically and
electrically engage the first fixed contact when a downward force
is imposed upon the inner frame.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a push-button switch with
an improved movable contact, which is widely used in many
electronic applications.
[0003] 2. Description of the Prior Art
[0004] A push-button switch using a conventional movable contact is
disclosed in U.S. Pat. No. 5,113,047. The conventional push-button
switch has a case made of synthetic resin in a form of a box with
an opening upper surface. A central stationary contact is exposedly
provided at the central of the inner bottom surface of the case,
and a pair of stationary contacts is provided on the inner bottom
surface surrounding the central stationary. A movable contact held
in the case has a dome-shaped configuration in the form of a
rectangular sheet, and disposes over the stationary contacts.
[0005] The movable contact is made by providing a leaf spring with
two slits. The movable contact has a periphery frame
interconnecting a central fragment and a pair of side fragments.
The central fragment is capable of contacting with the central
stationary contact by inverting motions, and the side fragments are
bent downwardly along a folding portion, which enable the side
fragments contact with the stationary contacts.
[0006] When an external force is exerted on the central fragment,
the central fragment may be inverted and contact with the central
stationary contact. While the force is removed, the converse
operation of the central fragment enables itself escaping from
contacting with the central stationary contact.
[0007] Although the conventional movable contact works well, it has
some problems need to be solved. The central fragment directly
connects to the periphery frame, thus it can easy acquire a strong
operating force. However, the strong operating force may affect the
operating-durability of the movable contact. At the same time, the
external force is exerted on the central fragment and transmitted
through a short C-shaped path to the side fragments. The transmit
path is so short that the stress on the movable contact may be very
high, which further shortens the lifetime of the movable contact
and the lifetime of the push-button switch as well.
[0008] Hence, a push-button switch with an improved movable contact
is required to overcome the disadvantages of the prior art.
BRIEF SUMMARY OF THE INVENTION
[0009] An main object of the present invention is to provide a
push-button switch with an improved movable contact, and the
movable contact has a good press-durability.
[0010] A push-button switch according to the present invention
comprises an insulative housing, a central fixed contact, a pair of
side fixed contacts, a movable contact, an actuator and a cover.
The cover engages with the housing and defines a guiding hole. The
central fixed contact and the side fixed contacts are fixed in the
housing, of which the side fixed contacts surround the central
fixed contact, and each has a pair of fixed contact terminals
extending out the housing. The movable contact is disposed over the
fixed contacts. The movable contact has a pair of side contacting
portions and a central contacting portion. The side contacting
portions contact with the side fixed contacts. The central fixed
contacting portion is capable of contacting the central fixed
contact by resilient deformation. The actuator is disposed on the
movable contact and has an operating portion projecting beyond the
guiding hole of the cover. The actuator actuates the movable
contact to contact the fixed contact.
[0011] The movable contact has a periphery frame, an inner frame
and an interconnecting portion interconnecting the periphery frame
and the inner frame. The side contacting portions are defined at
opposite edges in the periphery frame by bent down folding portions
thereof, and the central contacting portion is defined in the inner
frame by providing a pair of inner slits parallelly defined along.
A periphery slits is defined in the periphery frame between each
interconnecting portion and the corresponding side contacting
portion. A pair of opposite C-shaped slits is defined between the
inner frame and the periphery frame in a longitudinal
direction.
[0012] To compare with the conventional push-button switch, the
present invention comprises the improved movable contact. The
movable contact has the periphery frame, the inner frame and the
pair of interconnecting portions interconnecting the periphery
frame and the inner frame. The central contacting portion is
connected to the inner frame. In operation, an external force is
exerted on the central contacting portion. Then the force is
transmitted to the interconnecting portion through a C-shaped path,
and transmitted from the interconnecting portion to the side
contacting portions through a second C-shaped path. As the force
transmit path is obviously prolonged, the stress of the movable
contact can be lowed down, which ensures a reliable
press-durability of the movable contact.
[0013] Other objects, advantages and novel features of the
invention will become more apparent from the following detailed
description of a preferred embodiment when taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a push-button switch
corresponding to the present invention;
[0015] FIG. 2 is an exploded view of the push-button switch in FIG.
1;
[0016] FIG. 3 is another exploded view of FIG. 1;
[0017] FIG. 4 is a perspective view of a movable contact of the
push-button switch; and
[0018] FIG. 5 is a sectional view of the push-button switch in FIG.
1.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring to FIG. 2, a push-button switch in accordance with
the present invention comprises an insulative housing 1, a
plurality of fixed contacts 4, a movable contact 3, an actuator 5
and a cover 2.
[0020] The insulative housing 1 is a synthetic resin mold in a form
of a case with a base 11 opening to the air. The base 11 has a
periphery wall 12 extending upwardly therefrom, and a cavity 13 is
defined and enclosed by the periphery wall 12. The periphery wall
12 forms a plurality of positioning posts 121 on corner portions of
an upper surface thereof. The base 11 has a plurality of recesses
111 defined on corner portions of a lower surface thereof.
[0021] The plurality of fixed contacts 4 are fixed in the housing 1
by insert molding. The plurality of fixed contacts 4 comprises a
central fixed contact strip 41 and a side fixed contact strip 42,
which are parallel each other. The central fixed contact strip 41
has a central fixed contact 412 laterally extending from a central
portion thereof. The side fixed contact strip 42 has a pair of side
fixed contacts 422 laterally extending therefrom, wherein the side
fixed contacts 422 surrounds the central fixed contact 412. A
plurality of fixed contact terminals 411 and 421 is respectively
extended out of the housing from ends of the central fixed contact
strip 41 and the side fixed contact strip 42.
[0022] Also referring to FIG. 4, the movable contact 3 made of
conductive and resilient material has a rectangular dome-shaped
configuration. The movable contact 3 has a periphery frame 31, an
inner frame 32 and an interconnecting portion 34 interconnecting
the periphery frame 31 and the inner frame 32. A pair of opposite
C-shaped slits 37 is defined between the inner frame 32 and the
periphery frame 31 in a longitudinal direction. The periphery frame
31 has a pair of side contacting portions 35 located at opposite
edges by bent down folding portions for contacting the side fixed
contacts 422. A periphery slit 38 is defined between each
interconnecting portion 34 and the corresponding side contacting
portion 35. A central contacting portion 33 is formed by providing
a pair of inner slits 36 parallelly defined along in the inner
frame 32.
[0023] The actuator 5 comprises a holding portion 51. The holding
portion 51 has a columnar configuration. An operating portion 52 is
extended upwardly from the holding portion 51, which is also
columnar but smaller than the holding portion 51 in diameters. The
holding portion 51 has a concave defined at a lower surface
thereof. A pressing portion 511 is projected beyond the lower
surface of the holding portion 51 from the concave. The pressing
portion 511 has a plurality of radicalized portion interconnecting
the pressing portion 511 and the holding portion 51.
[0024] The cover 2 engages with the housing 1, and has a front wall
21 and opposite right and left walls 22 and 23. The opposite right
and left walls 22 and 23 are respectively extended rearward from
right and left edges of the front wall 21. The front wall 21 has a
guiding hole 210 defined at a central portion thereof corresponding
to the operating portion 52. Corresponding to the positioning posts
121 formed on the upper surface of the periphery wall 12, the front
wall 21 also defines a plurality of the positioning holes 211 at
corner portions thereof. A placing tab 212 is extended from a
central portion of a lower edge of the front wall 21. A holding tab
221 or 231 is formed at the right or left wall 22 or 23, which is
substantially formed by bending a tab partially cut from the right
or left wall 22 or 23. The placing tabs 222 and 232 (best shown in
FIG. 3) are extended from lower edges of the right and left walls
22 and 23.
[0025] In assembly, the fixed contacts 4 are mounted in the housing
1 by insert molding. The central fixed contact strip 41 and the
side fixed contact strip 42 are mounted parallel each other, the
side fixed contact 422 surrounds the central fixed contact 412, and
the fixed contact terminals 411 and 421 extend out of the housing
1. The movable contact 3 is received in the cavity 13 of the
housing 1. The side contacting portions 35 contact with the
corresponding side fixed contacts 422. The central contacting
portion 33 is correspondingly disposed over the central fixed
contact 412 for contacting with it in inverting operation. The
actuator 5 is mounted on the movable contact 3, of which the
pressing portion 511 is disposed on the central contacting portion
33. The cover 2 engages with the housing 1, of which the
positioning holes 211 couples with the positioning posts 121, the
operating portion 52 extends beyond the guiding hole 210, and the
holding tabs 221 and 231 holds the lower surface of the base
11.
[0026] In operation, an external force is exerted on the operating
portion 52, the central contacting portion 33 may be inverted to
contact with the central fixed contact 412, and an electrical
connection between the fixed contact terminals 411 and 421 is
established. When the external force is removed, the recover force
of the movable contact 3 enables the actuator 5 return to a normal
status, and the electrical connection is eliminated.
[0027] The structure of the movable contact 4 is the merit of the
improvement of the present invention. When the central contacting
portion 33 is pressed, the force is transmitted to the
interconnecting portion 34 through a C-shaped path, and then
transmitted from the interconnecting portion 34 to the side
contacting portions 35 through a second C-shaped path. As the force
transmit path is very long, the stress of the movable contact 4 can
be lowed down, which ensures a reliable press-durability of the
movable contact 4. Though the recover force of the movable contact
4 may also be lowed down, adjusting the curvature of the movable
contact 4 may solve this problem.
[0028] It will be understood that the invention may be embodied in
other specific forms without departing from the spirit or central
characteristics thereof. The present examples and embodiments,
therefore, are to be considered in all respects as illustrative and
not restrictive, and the invention is not be limited to the details
given herein.
* * * * *